Go to etrailer.com and you will find four Class III hitches that fit CX-9.
My question is that, w/o tow package, your CX-9 can only tow 2000lb safely.
Mazda DOES NOT even sell the hitch as an accessory if you you want to buy on
from them. You have to pull some string to get a dealer to order one for you as an
"replacement".
Anyway, I went with HiddenHitch. There is a video on eTrailer.com that shows positively this hitch can be installed easily. Mine is on the way.